Voltage-regrttlatino system



Feb. 3, 1931. a. w. JONES 1,790,712

VOLTAGE REGULA'IING SYSTEM Filed Sept. 20, 1929 In Ventorl Ben arn'm WJon es His Attcmn e 5.

Patented Feb; 3, 1931 UNITED STATES.

PATENT, OFFICE BBNJAIII W. 30m OI many, NEW YORK, ABSIGNOB TO omm ELECTRIC comm, A CORPORATION O1 NEW YORK VOLTAGI-BIGULA'I'I NG 818'!!! Ap lication fled September O0, 1989. Serial No. 384,073.

rent supply circuit.

Voltage regulators are often employed in order to maintain constant voltage for loads which are dependent for their proper oper- -ation on a fixed voltage, such as lamp loads for example. These regulators not only correct for changes in the voltage caused by variations in the voltage of the source, but also correct for changes in voltage due to the line dro caused by variation 1n the magnitude 0 the load itself. Such regulators are known in the art as feeder voltage regulators. They are divisible into two (118- tinct types, the induction type and what may be referred to as the step or switch ty e. My invention relates to-the latter type. ssentially the step type regulator comprises a two winding regulating transformer whose secondary winding is in the feeder clrcuit and whose primary winding is connected across the feeder circuit combined with a number of switches for either varying the voltage actually across the primary winding or for varying the proportion of the secondary winding which is actually bucklng or boosting the feeder voltage. Hereto ore such regulators have been characterized by V the following disadvantages in comparison with the induction type. They have been difficult to make fully automatic in operation, and in performing the switching operations it has been diflicult to provide a switching device which does not either open the circuit or short-circuit a portion of the transformer windings when going from one step to the next. Step regulators, however, have the following advantages with respect to induction regulators. They are cheaper to construct and due to the absence of heavy rotating parts, will respond with greater rapidity to voltage changes when they are i made fully automatic.

It is an object of my invention to provide a new and improved step type voltage regulater and particularly to provide a new and improved fully automatic step re tor.

t is a further object of my invention to provide a new and improved switching arrangement which does not break an established circuit until a second circuit is completed andwhich at the same time does not produce an objectionable short circuit.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

. Referring now to the single figure of the drawing, which is a dia ammatic illustration of an embodiment o my invention, 1 is a portion of an alternating current feeder circuit, whose right hand end connects to the source of alternating current suppl 1', and whose left hand end connects to the oad (not shown) supplied thereby. Connected across the load end of this feeder is a step down transformer 2, whose secondary winding is connected to wires 3 and 4, across which are connected the operating coils 5 to 9 of switching contactors 10 to 14 respectively, resistor 15, and a contact making voltage responsive device illustrated as relay 16, although it is to be understood that any suitable voltage responsive contact maker mightbe employed. Connected in the feeder circuit is the secondary winding of a bucking and boosting transformer 17, whose primary winding is connected to the four upper fixed contacts of contactor 10. Also connected across feeder 1 is an inductive device, shown as an impedance 18' which, as shown, is divided into sections 19 and 20. A second inductive device, shown as an impedance 21, shown as divided into sections 22 and23, is arranged to be connected successively across the sections of impedance 18, through the proper operation of the contactors 11 to 14 inclusive, Al]- though I have shown both inductive devices to be of the impedance type, it will occur to those skilled in the art that any other well known means for obtaining voltage steps, such as transformers with multi-tap secondaries might equally well be employed without departing from my invention in its type voltage however impedances have been shown.

Each of the contactors 11 to 14 inclusive are equipped with two upper fixed contacts, four lower fixed contacts, an upper pivoted contact 24and a lower movable contact 25. Con- .tactor 10 difiers' from contactors 1114 mclusive only in that it has four upper fixed contacts and two pivoted contacts 24. The

upper contacts of contactors 10--14 control theway the sections of impedances18 and 21 are connected to the primary wlnding of the boosting and bucking transformer 17. The lower contacts of the contactors control the energization of the proper operating coils of the contactors in response to movement of the pivoted contacts of relay 16. Contactors 10'14 are so constructed that when both of their operating coils are energized there is no tendency for their pivoted-contacts 24 to move but when one of the two operating coils is energized alone, the end of the p voted contact ad acent the energized coil is attracted and moves toward this coil. These contactors are unique in that when their p1voted arms or contacts 24 swing from one position to the other, there is neither a temporary short circuit between the two fixed contacts, nor is the circuit whlch was previously closed opened until the circuit which is to be made has been completed. This is because during the time that the pivoted contact has disengaged one fixed contact and before it has enga ed the other fixed contact an arc is drawn etween the contacts wh ch have been disen aged and this are persists until the pivoted contact engages the other fixed contact. The reason for this being that after this engagement the voltage tending to maintain the arc is merely the voltage across one section of impedance, which is not suificient to maintain the arc. The rapid action of the contactors prevents injury to their contacts by the arc. Voltage responsive relay 16 comprises an operating coil connected between conductors 3 and 4, a plunger and pivoted contacts 26 and 33 operated thereby. Relay 51, comprising coils 50 and 52, a plunger and contacts 58, 60 and 83 is under the control of relay 16 and functions to cause the operation of contactors 11 and 12 in proper se uence. Relay 63, comprising operating coi s 62 and 70, a plunger operated thereby and contacts'68, 69 and 75 is under the control of relay 51 and functions to control the proper sequence of operation of contactors I3 and 14.

The operation of my system is, in general, as follows: Assuming a change in voltage on feeder 1, relay 16 will respond to first cause contactor 10, the upper contacts of which constitute a reversing switch, to take n such a position that when the primary win mg of transformer 17 is connected to the various sections of the impedances 18 and 21, the volttactor 12 will operate to connect impedance 21 across section 20 of impedance 18 in such a way that the primary winding of transformer 17 is connected across section 19. Contactor 14 will then operate to connect the primary winding of transformer 17 across impedance sections 19 and 23 in series. If this does not restore the voltage to normal, contactor 13 will operate to connect the primary winding of transformer 17 across impedance sections 19, 23 and 22in series, which amounts to connecting it across sections 19 and 20, or in other words directly across the feeder. This, therefore, is as far in one direction as the system can go. If the feeder voltage now changes in the opposite direction contactors 1114 inclusive reverse their operation, and if the voltage has gone past normal in the o posite direction, reversing contactor 10 will operate and contactors 11-14 will again go through the series of operations previously described. It is to be noted that in the operation just described a vernier-lilge action is secured by connecting the impedance 21 successively across the sections of impedance 18. In actual practice the effect of this Vernier-like action is increased by increasing the number'of sections in impedance 21. While to secure ater accuracy of regulation, the number 0 sections in impedance 18 is also increased in actual practice. Thus, with five sections in each impedance and a corresponding increase in the number of contactors, it is possible to obtain fifty voltage steps, not counting the position of the elements at normal voltage. For purposes of simplicity of illustration and description, however, but two sectionsin each impedance have been here disclosed, the principle of operation being, however, identical, no matter what number of sections above two for each impedance are used.

Referrin now to the operation of my system in detail. The system naturally lends itself to description in two distinct parts, namely, the operating circuits which cause the contactors to go through a predetermined sequence of operation and the circuits controlled by the operation of the contactors in this sequence for bucking or boosting the feeder voltage. I will first describe the operating circuits. Assume a rise in voltage on feeder 1. This rise will be transmitted through transformer 2 to wires 3 and 4. The increase in voltage between wires 3 and 4 will cause relay 16 to raise its armature and cause engagement between the upper and lower pivoted contacts and the upper and middle fixed contacts respectively. A circuit will then be completed from wire 3, through contacts 26 and 27 of relay 16, conductor 28, conductor 29, contacts 30, 25 and 31 of contactor 11, conductor 32, left hand ope-rating coil 5 of contactor 10, to conductor 4. The circuit just traced, therefore, short-circuits the right hand operating coil of contactor 10. However, as pivoted contacts 24 of contactor 10 arealready as near as possible to left hand coil 5 of contactor 10, no movement takes place. Reversing contactor 10 is therefore in the proper position for operating transformer 17 to buck the increase in feeder voltage. At the same time, a second circuit is completed as follows, conductor 4, contacts 33 and 34 of relay 16, conductor 35, contacts 36, 25 and 37 of contactor 10, resistance 38, conductor 39, conductor 40, contacts 41, 25 and 42 of contactor 13, conductors 43, 44, contacts 45, 25 and 46 of contactor 12, conductor 47, right hand operating coil 6 to wire 3. Left hand operating coil 6 is, therefore, shortcircuited and contactor 11 is actuated to turn arm 24 thereof counterclockwise and move contact 25 thereof downwardly. Connected between conductors 39 and 44 by means of conductors 48 and 49 is a coil 50 of relay 51. However, as this coil is short-circuited the relay is not operated. Keeping in mind that conductor 39 is connected to conductor 4 a circuit will now be completed from conductor 39, conductor 48, coil 52 of relay 51, conductors 53, 54, contacts/55, 25 and 56 of contactor 11, conductor 57 ri ht hand operating coil 7 to conductor 3. owever, the resistance of coil 52 is high enough to prevent contactor 12 from operating although it is not so high but that the current through it causes relay 51 to operate and move itscontact 58 downwardly. A circuit is then completed from conductor 4, through conductor 59, contacts 60 and 58, conductor 61, coil 62 of relay 63, conductor 64, contacts 65, 25 and 66 of contactor 14, conductor 67, right hand operating coil 8 to conductor 3. The resistance of coil 62 is sufliciently high to prevent the operation of contactor 13 but enough current passes to cause contact arm 68 to be pulled down into engagement with contact 69 thereof, short-circuiting coil 62 and causing contactor. 13 to operate. A circuit will then be completed from conductor 61, coil 70 of relay 63, conductor 71, contacts 72, 25 and 73 of contactor 13, conductor 74, right hand operating coil 9 to wire 4. Completion of this circuit causes contact arm 68 torise when it engages contact 75 thereof, short-circuiting coil 70 and causing contactor 14 to operate. The reason relay 63 is used, instead of connectin conductor 61' directly to conductors 64 an 71 is that a. time factor is thereby introduced which gives relay 16 time to operate if the operation of the prior contactor has brought the voltage to normal. Without this, contactor 14 would operate so soon after contactor 13 that the system mi ht under or over compensate for voltage c anges, causing what would be akin to hunting in a vibratory ty voltage regulator. Coil 52 of relay -51 wi 1 now be short-circuited and contactor 12 caused to operate because of the establishment of the followin short" circuit. Conductor 39, which it wil be remembered is connected to conductor 4, contacts 76, 25, 77 of contactor 14, conductor 78. This will allow sufficient current to flow through conductor 54, contacts 55,25, and 56 of contactor 11 and conductor 57 to cause right hand operating coil 7 to operate contactor12. As soon as contactor 12 operates, a circuit is completed from conductor 4, to conductor 39 as previously described, conductor 48, coil 50 of relay 51, conductors 49 and 44, contacts 7 9, 25 and 80 of contactor 12, resistance 15, conductor 81 to conductor 3. Completion of this circuit causes relay 51 to move its contact 58 into engagement with its fixed contact 83. A circuit will then be completed from conductor 3, through conductor 82, contacts 83 and 58 of relay 51, conductor 61, coil 70, conductor 71, contacts 72, 25, 73, conductor 74, left hand operating coil 9 to conductor 4. Relay 63 then short circuits coil 70 and contactor 14 operates. Operation of contactor 14 allows a circuit to be completed from conductor 3, through conductor 82, contacts 83, 58, conductor 61, coil 62, conductor 64, contacts 65, 25, 66, conductor 67, left hand operating coil 8 to conductor 4. Relay 63 then short-circuits coil62 and contactor 13 operates. This coinpletes the cycle of operations if the voltage rise on feeder 1 is sufiiciently great. If the rise has been small relay 16 will return to its mid position before this cycle has been completed, for as each contactor operates the increase in feeder voltage is increasingly opposed, as has already been stated.

Should the feeder voltage new fall, for example should it fall below the normal voltage at which relay 16 is in its mid osition,

conductor 3'will be connected to con uctor 39 through contacts 26 and 84 of relay 16, conductor 35, contacts 36,25, and 37 of contactor not energized is that it is short-circuitedthrough conductor 40, contacts 41, 25, 42 and conductor 43, the circuit containing this shortcircuit being completed through conductor 44, contacts 79, 25, 80 and resistance 15, to conductor Resistance 15 is of equal magnitude to t resistance of coils 5-9 inclusive. As cond ctor 61 is now connected to conductor 4,'co tactors 13 and 14 will operate in the orde mentioned, through circuits which have already been traced in connection with the initial operationof contactors 13 and 14. As soon as contactor 13 operates the short circuit around coil 50 of relay 51 is removed, and as soon contactor 14 operates a short circuit arou rfd coil 52 of relay 51 is completed through contacts 76, 25, 77 and conductor 78. Relay 12 therefore operates. The circuit through coil 50 from conductors 3 to 48 is then throu h conductors 49, 44, contacts 45, 25, 46, com? ating coil 6 to conductor 4. This circuit through operation of relay 51 causes conductor 61 to be connected to conductor 3 through contacts 58 and 83 and conductor 82. Connecting conductor 61 to conductor 3 causes contactors 13 and 14 to return to the positions shown in the drawing in reverse order, throu h circuits which have already been trace As soon as contactor 13 has returned to the position shown in the drawing, coil 50 of relay 51 is short-circuited through conductor 40, contacts 41, 25 and 42 of contactor 13 and conductor 43. Enough current therefore flows through conductor 44, contacts 45, '25 and 46 of contactor 12, conductor 47 and left hand operating coil 6 to return contactor 11 to the position shown in the drawing. As soon as contactor 11 returns to its original position a circuit is completed from conductor 4 through contacts 33 and 27 of relay '16, conductors 28 and 29, contacts 30, 25, and 31 of contactor 11, conductor 32, right hand operating coil 5 to conductor 3. Completion of this circuit causes reversing contactor 10 to operate. Operation of reversing contactor 1O breaks the connection between conductor's 3 and 39 and completes a connection between conductors 4 and 39, as follows. Conductor 4.. contacts 33 and 27 of relay 16, conductor 28, contacts 87, 25 and 88 of contactor 10, resistance 38 to conductor 39. Therefore, so long as relay 16 remains in the down position conductor 39 will be connected to conductor 4 and so long as the connection is maintained the contactors will repeat the series 'of operations which were previously described in detail through circuits which have already been traced. That is, first contactor 11 will operate, then contactors 13 and 14 will operate in the order mentioned, then contactor 12 will operate, then contactors 13 and 14 will be restored in reverse order. 7

If new the feeder voltage should again rise, conductor 39 would be connected to conuctor 47, left hand oper-.

of the contactors would be reversed as in the prior detailed description of the reverse operation.

It should be distinctly understood that the operation of the contactors is always under the primary control of rela 16 and that this relay is responsive to an e ectrical condition of the feeder, which as shown is the feeder voltage. Thus the series of operations of the contactors may be arrested at any point or reversed in response to changes in the feeder volt-age.

- Turning now to a detailed description of the circuits controlled by the operation of the contactors. These circuits govern the connections between the main impedance 18, the Vernier im edance 21 and the primary winding of the ucking and boosting transformer 17. With the elements in the positions shown the primary winding of transformer 17 has no voltage across it, in other words it is not connected across any of the various impedance sections. When now contactor 11 operates'in response to a rise-in fee-der voltage, Vernier impedance 21 is connected across section 19 of impedance 18 as follows, conductors 89, 90, contacts 91 and 24 of contactor 12, conductor 92, Vernier impedance 21, conductor 93, contacts 24 and 94 of contactor 11 and conductor 95 to the other end of sec tion 19. When contactor 13 now operates, the primary windin of transformer 17. is connected across sectlon 22 of impedance 21, which is in turn connected across section 19 of impedance 18 through the following cir cult, conductor 96, contacts 97 and 24 of reversing contactor 10, conductor 98, contacts 24 and 99 of contactor 14, conductor 100, contacts 24 and 101, conductor 102, section 22, conductor 92, contacts 24 and 91 of contactor 12, conductors 90 and 103, contacts 24 and 104 of reversing contactor 10 and conductor 105 to theother side of the primary winding of transformer 17. The voltage across the transformer primary winding will therefore equal the impedance drop in section 22. The voltage induced in the secondary winding will then buck the increase in feeder voltage. If this bucking voltage is not enough to return the voltage to normal, contactor 14 will operate, thereby drawing an arc between contacts 99 and 24 until contact is established between contacts 24 and 109 of contactor 14. The effect of this will be to break the connection from conductor 98 to 102 and make a connection from conductor 98 to 93 thereby connecting the primary winding of transformer 17 across both sections of impedance 21 or in other words directly. across section 19 of impedance 18, through conductor 95. If this does not restore the feeder voltage to normal, contactor 12 operates, which has the effect of connecting conductor 92 to the me -Ira tacts 106 and 24 of contactor 12 and conductor 107, at the same time opening the circuit at contact 91. Vernier im ance 21 is other side of now across section 20.0f impe ce 18 with the instantaneous polarity of its terminals reversed. However, no change has lace in the primary winding circuit of transormer 17 Contactor 14 now restores, which has the effect of connecting the primary winding of transformer 17 .across section 19' of impedance 18 and section 23 dot-vernier impedance .21, conductor 98, contacts 24 and 99 of contactor 14, conductor 100, contacts 24 and 101 of contactor 13, conductor 102,

section 23, conductor 93, .contacts 24 and 94- of contactor 11, conductor 95, section 19, conductors 89 and 103, to the other side of reversing contactor 10. If this does not restore the voltage, contactor 13 restores, thereb connecting reversing contactor 10 and the primary winding of transformer 10 directly across feeder 1, as follows, conductor 98,. contactor 14, conductor 100, contactor 13, conductors 108 and 92, contactor 12, conductor 107, feeder 1 conductors 89 and 103 to the reversing contactor 10. This obviously represents the position for maxi mum bucking. Should the feeder voltage now increase, the steps which have been just described will be reversed until when contactor 11 restores, reversing contactor 10 will operate. If the voltage has dropped sufiiciently, the connections which have ust been described will obviously again be made, although the transformer will be acting as a booster transformer.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention and I, therefore, aim in the a pended claims to cover all such changes an modifications as fall within the true spirit and scope of my invention.

W'ha't Iclaim as new and desire to secure by Letters Patent of the United States, is:

1. In combination, an alternating current circuit, a transformer, one of whose windings is connected in said circuit, a main inductive device, a vernier inductive device and means operative in accordance with the variations in voltage of said circuit for connecting the other winding of said transformer across said circuit successively through varying proportions of said main inductive device, in steps, and for inserting in the circuit of said other winding said vernier inductive device and varying the magnitude of said vernier inductive device between its two extremes for each step made on said main inductive device, whereby the voltage induced in the transformer winding connected in said alternating current circuit equals and opposes any change in the voltage of said alternating current circuit.

2. In combination, an 'altemating current circuit, a transformer, one of whose windings is con ected in said circuit, a main impedance,

a verm r impedance, and relay means responsive'to variations in voltage of said circuit for connecting the other winding of said transformer across said circuit su ccessivel through varying proportions of said imped ance, in steps, and forinserting in the circuit of said other winding said vernier impedanceand varyin the magnitude of said vernier impedance 'etween its two extremes for each step made on said impedance, whereby the voltage induced in the transformer winding connected in said circuit equals and opposes any change in the voltage of said circuit.

3. In combination, an alternating current circuit, a transformer, one of whose windings is connected in said circuit, one terminal of the other winding being connected to one side of said circuit, an inductive device connected across said circuit, a second inductive device and means responsive to changes in volt-- age of said circuit for connecting said second inductive device across different sections of said inductive device said means also connecting the other terminal of said other winding end to the other, between each time said sec- 0nd inductive device is connected across a different section of said inductive device.

4. In combination, an alternating current circuit, a transformer one of whose windings is in said circuit, means connecting one terminal of the other winding to one side of said circuit, an impedance, divided into sections, connected across said circuit, a second impedance, means for connecting said second impedance successively across sections of said impedance in such a manner that a different end of said second impedance is alternately connected to the outer ends of adjoining sections, while the opposite end of said second impedance remains connected to the junction ings is connected in said circuit, means con necting one terminal of the other winding of said transformer to one side of said line, an impedance, divided into sections, connected across said line, a second impedance, control means for connecting said I second impedance successively across the sections of said impedance in such a way that the instantaneous polarity of the terminals of said second impedance is reversed each time said second impedance is connected from one section to the next of said impedance, additional control means for connecting the other terminal of the other winding of said transformer step by step from one end ofsaid second impedance to the other before each change in connections of said second impedance and reversing said step by step connection after each said change, and means responsive to an electrical condition of said-alternating current circuit for governing the o eration of said control means.

6. In com ination, an alternating current circuit, a transformer, one of whose windings is connected in said circuit, means connecting one terminal of the other wmdmg of said transformer to one side of said line, an impedance, dlvided mto sections, connected across said line, a second impedance, control means for connecting said second impedance successively across the sections of said impedance inisuch a way that the-instantaneous polarity of the terminals of said second impedance is reversed each time said second impedance is connected from one section to the next of said impedance, additional control means for connectin the other terminal'of the other winding 0% said transformer step from one end of said second impedance to the other before each change in connections of said second impedance and reversing said step by step connection after each said change, means responsive to an electrical condition of said alternating current circuit for governing the operation of said control means, and further control means governed jointly b said last mentioned means and both 0 said above-mentioned control means for reversing the con nections of one of the windings of said transformer when the value of said electrical condition is on one side of a given value and said control means are in one extreme position.

7. In combination, a source of electrical energy, an impedance, means connecting one terminal of said impedance to one terminal of said source, a plurality of separate contacts each connected to different connection points of said impedance, a like number of contacts-cooperating with each of the firstmentioned contacts, two of said cooperating contacts being normally in engagement, means connecting each of the last-mentioned contacts to the other terminal of said source, and means for separating said engaged pair of cooperating contacts, whereby an arc is drawn, and for causing engagement of an other of said cooperating contacts before said are is extinguished, the voltage drop in said impedance being insuflicient to maintain said arc.

8- In combmation, a circult including a source of current supply an im dance and a switch for cutting saidfimpe ance in and out of said circuit without opening said circ'uit or short-circuiting said impedance, comprising a pair of cooperating contacts which complete said'circuit "through said 1m dance when inengagement, a second pair of cooperating contacts which complete said circuit without including said impedance, when in engagement, one of said pa1rs of contacts being normally in engagement, and means for separating said normally engaged pair of contacts and causing engagement of said other pair of cooperating contacts before the are between said contacts which have been separated is broken, the voltage drop across said impedance being msufiicient to maintain said arc.

In witness whereof, I have hereunto set my hand this 19th day of September, 1929.

- BENJAMIN W.- JONES. 

